fix: use posix path

[drazisil]

This changes path to use path.posix per https://nodejs.org/dist/latest-v14.x/docs/api/path.html#path_windows_vs_posix

Thanks @eddiemoore !

This also runs tests on Windows prior to building.

[codecov]

Codecov Report

Merging #141 (0f6f601) into master (ed0359b) will decrease coverage by 0.18%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #141      +/-   ##
==========================================
- Coverage   91.57%   91.39%   -0.19%     
==========================================
  Files          30       15      -15     
  Lines        1092      546     -546     
  Branches      210      105     -105     
==========================================
- Hits         1000      499     -501     
+ Misses         40       20      -20     
+ Partials       52       27      -25     

Flag	Coverage Δ
alpine	91.39% <100.00%> (-0.19%)	⬇️
linux	91.39% <100.00%> (-0.19%)	⬇️
linux-without-git	∅ <ø> (∅)
macos	91.39% <100.00%> (-0.19%)	⬇️
macos-without-git	∅ <ø> (∅)
windows	90.84% <100.00%> (-0.74%)	⬇️
windows-without-git	∅ <ø> (∅)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/helpers/files.js	92.85% <100.00%> (ø)
src/ci_providers/provider_circleci.js	90.32% <0.00%> (-3.23%)	⬇️
...ci/project/src/ci_providers/provider_appveyorci.js
...roject/src/ci_providers/provider_azurepipelines.js
...project/src/ci_providers/provider_githubactions.js
C:/Users/circleci/project/src/helpers/git.js
...leci/project/src/ci_providers/provider_circleci.js
...:/Users/circleci/project/src/ci_providers/index.js
...ircleci/project/src/ci_providers/provider_local.js
C:/Users/circleci/project/src/helpers/logger.js
... and 7 more

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[drazisil]

Looks great! https://codecov.io/gh/codecov/uploader/tree/0f6f6018eb13262761ae0a3c8d40b4b828b562a7

As far as the coverage drop... it doesn't like blank lines? 🤷‍♀️